Noise, while being an irritation, is also a cause of hearing loss when the ears are either subjected to a single loud noise or are repeatedly subjected to levels of noise above a safe level. Such noise is increasingly becoming an issue in industrial and other workplace settings where machinery operates. While some efforts may be made to reduce noise produced by machinery, the exposure to high levels of noise, or even repeated exposure to lower levels of noise, may lead to hearing loss.
For instance, the Occupational Safety and Health Administration (“OSHA”) within the United States Department of Labor has recognized that prolonged or even short exposure to some sound levels may lead to permanent hearing loss. Consequently, OSHA has set forth regulations requiring employers to develop and implement a hearing conservation program whenever exposure over an eight hour period averages 85 decibels or greater. An employer may even be required to provide protective equipment in some cases. By way of example, if an employee is subjected to sound exceeding an average of 90 decibels within an eight hour period, or sound exceeding an average of 115 decibels for fifteen minutes or less, the employer may be required to provide protective equipment. For sound levels between 90 and 115, different exposure periods may result in requirements for employer-provided ear protection.
Ear protection has traditionally taken the form of earplugs, semi-insert ear plugs, or ear muffs. Ear plugs may be pre-molded or moldable, and can be inserted in the ear to block the ear canal. Semi-insert ear plugs can include ear plugs held over the ends of the ear canal by a rigid headband. Ear muffs may include a pair of sound-attenuating ear cushions attached to hard outer cups. The ear cushions fit around the ear and the hard outer cups are connected by a head band.
Each type of ear protection may be effective in attenuating some noise, whether the noise originates at a workplace, at home (e.g., while vacuuming, in the workshop, etc.), at a sporting event (e.g., motor sports), during travel (e.g., on an airplane ride), or at other locations. The effectiveness of such devices also can provide certain drawbacks. For instance, when an earplug is in a person's ear, the person may not be able to hear music playing on the radio, hear announcements at a motorsports race, or the like. While a person could instead use an earbud connected to a radio or media player, earbuds have not traditionally been designed to prevent hearing loss. Earbuds may therefore not sufficiently attenuate external noise, thereby allowing ear damage. Headphones that do attenuate external noise (e.g., noise cancelling headphones) are traditionally large and oversized, and therefore lack discreteness, or may be easily damaged in small spaces.